Synthesis of lithium difluoro(oxalate)borate(LiODFB), phase diagram and ions coordination of LiODFB in dimethyl carbonate

A new two-step synthetic method was successfully developed to simplify the recrystallization process of lithium difluoro(oxalate)borate(LiODFB).Meanwhile,the purity of LiODFB as-prepared was determined by NMR,ICP-AES and Karl Fisher measurements,respectively.The as-prepared LiODFB presents a high purity up to 99.95%.Its metal ions and water contents are under good control as well.Besides,its structure information and thermal properties were confirmed by FTIR,Raman and DSC-TGA analyses,respectively.LiODFB exerts fine thermostability and hypo-water-sensitivity and its structure information agrees well with previous literature.Furthermore,a combination of phase diagram and Raman spectroscopy were utilized to study the thermal phase behavior and ions coordination of LiODFB-DMC binary system to optimize the synthesis and recrystallization process.Although there are three types of molecular interaction forms(CIPs,AGG-IIa,AGG-IIIb)in LiODFB-DMC binary system,LiODFB can only be isolated as large single crystal solvate as LiODFB·(DMC)3/2 by slowly cooling subjected to the nucleation kinetics.Therefore,the fundamental information of our work is helpful in accelerating the application of LiODFB in Li-ion secondary batteries.

Sodium Alginate/Carboxyl-Functionalized Graphene Composite Hydrogel Via Neodymium Ions Coordination

A facile method for the preparation of sodium alginate（SA）/carboxyl-functionalized graphene（G-COOH）composite hydrogel was developed. Based on the coordination ability of lanthanide ions to the carboxyl groups, a series of hydrogel derived from different ratios of SA and G-COOH was fabricated by neodymium（Nd3＋） ions coordination. A relatively uniform layered structure was recorded by SEM at the interior of SA/G-COOH hydrogel. Several parameters such as water content, swelling ratio（SR）, tensile test and solvent resistance were also investigated. The SA/G-COOH composite hydrogel showed excellent mechanical strength, and the tensile strength of SA/G-COOH composite hydrogel reaches 53.72 MPa at high water content. Due to the coordination ability of Nd3＋ ions, the hydrogel also exhibited an excellent solvent resistance and stability.

Composite Model of Interracial Stepwise Ion/Coordination Particle Exchange-Electrostatic Exchange——Ionic Strength Effect on the Interaction Between Minor Metal Ion and Solid Particle in Seawater

It is the first time in experiment that we have found that the ionic strength effects on E(%)-pH curves of the systems with clay minerals as solid particles and those systems with hydrous oxides as solid particles, are 'right-left shift phenomenon' and 'left monodirectional shift phenomenon', respectively.The corresponding ionic strength effects on isotherms are 'downward-upward shift phenomenon' and 'upward monodirectional shift phenomenon', respectively.All the four phenomena are consistent with each other.In order to explain the above phenomena, the composite model of interracial ion/coordination particle exchange-electrostatic exchange is put forward to make a unified explanation and quantitative treatment.From the structures of the two kinds of materials——clay minerals and hydrous oxides, we know that the former has two kinds of exchange actions, i.e. when one increases,the other decreases, which makes the position of curves shift didirectionally,while the latter only has interfacial stepwise ion/coordin ation particle exchange,the curves of which shift therefore monodirectionally.The calculated results of the model accord with the experimental.

Highly stretchable and self-healable ionogels with multiple sensitivity towards compression,strain and moisture for skin-inspired ionic sensors

Ionic skin(I-skin)is an emerging skin-inspired sensor that has received increasing interest for the next-generation wearable electronics.However,profound challenges for I-skin remain in achieving multiple signal responses(e.g.,strain,pressure,and humidity)and self-healability to fully mimic human skin.Herein,a Fe;ion-coordinated poly(acrylic acid)ionogel(PAIFe)with high stretchability,extreme temperature tolerance,and self-healing capability is prepared by a dynamic ionic cross-linking strategy.The ionic coordination in the PAIFe contributes to the formation of a highly dynamic network,achieving its high-efficient and reliable self-healing performance even at a low temperature of-20℃.Using of 1-butyl-3-methylimidazolium tetrafluoroborate([BMIm][BF^(3+)])as the solvent achieves a widetemperature tolerance of the PAIFe under low and high temperatures.More interestingly,a humidity sensing function is realized in the PAIFe by skillfully utilizing the hygroscopic properties of[BMIm][BF_(4)].The resultant PAIFe is proof-ofconcept demonstrated as a deformation-tolerant ionic conductor in a skin-inspired ionic sensor,showing a variety of sensory capabilities towards compression,strain and humidity.